I was called to switch a guy from cable to dsl . Everything was working fine on cable, 4 pc's and a Linksys wireless 4 port router...

I disconnected pc #1 from router and plugged directly into dsl modem, ran the SBC software and got online. Shut everything down, hooked the modem to the router and pc#1 to the router, and fired up. PC#1 will not go on the internet but see's the other pc's in the network, and can access files from them. The other 3 pc's all see the internet and the network.
I connect pc#1 directly into the cable modem and it see's the internet fine.
I have tried everything I can think of, but still cannot access the internet thru the router, with pc #1. I even tried a different port on the router.